Lab Testing for Influenza

The San Mateo County Public Health laboratory provides PCR testing for influenza virus. Submit specimens from ICU or deceased patients with suspected influenza for PCR testing directly to the Public Health Lab. All specimens should be sent in viral transport media (VTM), regardless of rapid flu test results. Rapid flu specimens are NOT acceptable for RT-PCR testing.

San Mateo County Lab Testing Instructions

1. Collect up to 2 nasopharyngeal Dacron swabs from the patient with ILI; place them in a standard container with 2-3 ml of viral transport media (VTM).
   Specimens should be collected within 24-72 hours after the initial onset of symptoms, and no later than 5 days after onset. If the patient is hospitalized with pneumonia, specimens from the lower respiratory tract (i.e. tracheal aspirate, bronchoalveolar lavage), should also be obtained.
   • Specimen Collection Demonstration Video (New England Journal of Medicine)
   • Nasopharyngeal specimen collection written instructions (NYC Health Department)
      
2. Refrigerate and store the specimen at 4° C and send on cold packs if they can be received by the laboratory within 5 days of the date collected. If samples will be received by the laboratory in 5 or more days, they should be frozen at - 70° C, or below, and shipped on dry ice.
    
3. Complete the Influenza RT-PCR Request Form [PDF]. The Public Health Lab WILL NOT run specimens without this form.
    
4. Ship specimens to:
   San Mateo County Public Health Laboratory (PHL)
   225 37th Avenue, Room 113
   San Mateo, CA 94403

San Mateo County Public Health Lab is open Monday through Friday, 8:00 am to 5:00 pm. For more information, call (650) 573-2500.

• Respiratory Infection Testing Algorithm [PDF]
• CDC Lab Testing Guidelines